import time
incomplete_sign =50
print('='*23+'开始下载'+'='*25)
for i in range(incomplete_sign + 1):
    completed ="*" * i
    incomplete ="." * (incomplete_sign -i)
    percentage = (i / incomplete_sign)*100
    print("\r{:.0f}%[{}{}]".format(percentage,completed,incomplete),end="")
    time.sleep(0.5)
print("\n" + '='*23+'下载完成'+'='*25)